In a conventional IC tester, a probe card with probes is installed in the test head of a tester. A flexible portion have been specially designed in the probes of a probe card which can scrub through the oxide layer on the bonding pads of an IC chip under test to ensure good electrical contacts. Conventional methods of manufacturing the probes include metal casting, extraction, or pressing, however, a tailor-made tooling is required which is very expensive where the shapes of the probes are very limited. Moreover, as the pitches of the bonding pads become smaller and the densities of the bonding pads become higher, probes manufactured by conventional methods cannot meet the fine-pitch and high-density requirement of the bonding pads.
As revealed in R.O.C. Taiwan Patent publication No. 517320, John et al. discloses a method of manufacturing a plurality of flexible probes in a row using vapor deposition. As shown in FIG. 1, a substrate 10 is provided which has a flat surface 11 where a plurality of probes 20 are formed on the flat surface 11 by sputtering, plating, or chemical-vapor deposition. A connecting bar 21 is connected to the probes 20. Each probe 20 has a contact point 22 and a flexible portion 23 bent in the horizontal direction along the flat surface 11 of the substrate 10. The probes 20 are assembled to a probe card.
As shown in FIG. 2, an IC 30 under test has a plurality of bonding pads 31. During chip probing, the contact points 22 of the probes 20 will contact the bonding pads 31 of the IC 30. While the contact points 22 of the probes 20 are probing the bonding pads 31, the flexible portion 23 of the probes 22 due to the overdrives will allow the contact points 22 to shift in the same horizontal direction 32 to penetrate the oxide layer on the bonding pads 31. However, the penetrating shift direction 32 is parallel to the arranging direction of the bonding pads 31 which cause electrical shorts between the probes 22 and damages to the IC, the probe card or even the tester.